Volatile Temporary Table (VTT) vs Global Temporary Table (GTT)

VTT are session scoped whereas GTT is also a session scoped but its DDL can be accessed by other sessions because it is stored in data dictionary.

GTT takes up space from temporary space where as VTT takes up space from spool.

GTT survive TD system restarts where as VTT does not.

GTT allows index to be created where as VTT does not.

In a single session 2000 GTT can be materialized where as in case of VTT the count is only 1000.

GTT allows some constraints to be created on where as VTT does not.